[PATCH AUTOSEL 4.14 42/58] scsi: NCR5380: Add disconnect_mask module parameter

From: Sasha Levin
Date: Wed Dec 11 2019 - 10:31:30 EST


From: Finn Thain <fthain@xxxxxxxxxxxxxxxxxxx>

[ Upstream commit 0b7a223552d455bcfba6fb9cfc5eef2b5fce1491 ]

Add a module parameter to inhibit disconnect/reselect for individual
targets. This gains compatibility with Aztec PowerMonster SCSI/SATA
adapters with buggy firmware. (No fix is available from the vendor.)

Apparently these adapters pass-through the product/vendor of the attached
SATA device. Since they can't be identified from the response to an INQUIRY
command, a device blacklist flag won't work.

Cc: Michael Schmitz <schmitzmic@xxxxxxxxx>
Link: https://lore.kernel.org/r/993b17545990f31f9fa5a98202b51102a68e7594.1573875417.git.fthain@xxxxxxxxxxxxxxxxxxx
Reviewed-and-tested-by: Michael Schmitz <schmitzmic@xxxxxxxxx>
Signed-off-by: Finn Thain <fthain@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/scsi/NCR5380.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/NCR5380.c b/drivers/scsi/NCR5380.c
index 21377ac71168c..79b0b4eece194 100644
--- a/drivers/scsi/NCR5380.c
+++ b/drivers/scsi/NCR5380.c
@@ -129,6 +129,9 @@
#define NCR5380_release_dma_irq(x)
#endif

+static unsigned int disconnect_mask = ~0;
+module_param(disconnect_mask, int, 0444);
+
static int do_abort(struct Scsi_Host *);
static void do_reset(struct Scsi_Host *);
static void bus_reset_cleanup(struct Scsi_Host *);
@@ -946,7 +949,8 @@ static bool NCR5380_select(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
int err;
bool ret = true;
bool can_disconnect = instance->irq != NO_IRQ &&
- cmd->cmnd[0] != REQUEST_SENSE;
+ cmd->cmnd[0] != REQUEST_SENSE &&
+ (disconnect_mask & BIT(scmd_id(cmd)));

NCR5380_dprint(NDEBUG_ARBITRATION, instance);
dsprintk(NDEBUG_ARBITRATION, instance, "starting arbitration, id = %d\n",
--
2.20.1